Alfonso Ibarreta, Ph.D., PE, CFEI,
\nTimothy Myers, Ph.D., PE, CFEI, CFI,
\nJames Bucher, Ph.D., CFEI and
\nKevin Marr, Ph.D., CFEI
\nExponent, USA<\/p>\n
Presented at\u00a0International Symposium on Fire Investigation<\/a>, 2012<\/p>\n ABSTRACT<\/p>\n Natural gas, composed mainly of methane, is in some ways similar to propane gas. Both fuels have similar\u00a0energy densities per unit mass, and similar laminar premixed flame burning velocities. However, propane\u00a0explosions have been shown to produce higher overpressures in unconfined explosion tests when compared to\u00a0methane. In vapor cloud explosion modeling, methane is considered to be a \u201clow\u201d reactivity fuel, while propane is\u00a0listed as a \u201cmedium\u201d reactivity fuel. In closed vessel explosion testing, the maximum rate of pressure rise for\u00a0propane is almost twice than that for methane (based on KG\u00a0 values reported in NFPA 68 (2007) Standard for\u00a0Explosion Protection by Deflagration Venting , table E.1).<\/p>\n This study provides a direct comparison of the explosion severity between commercial propane and natural gas.\u00a0Empirical correlations available for vented vessel explosions and unconfined Vapor Cloud Explosions (VCEs) are\u00a0used to predict the difference in overpressure expected for a commercial propane explosion versus natural gas\u00a0explosion. Although the maximum laminar burning velocity associated with propane is only about 15% higher than\u00a0that associated with methane, commercial propane explosions are expected to result in overpressures that are about\u00a040% higher than that of a natural gas explosion under identical conditions with a perfectly-mixed nearstoichiometric\u00a0fuel-air mixture, based on empirical correlations.<\/p>\n In addition to the laminar burning velocity, other fundamental differences in the fuels may also play an important\u00a0role in the explosion severity. Propane has a slightly higher expansion ratio than methane when undergoing\u00a0combustion. The mass diffusivity of propane and methane are also quite different, making the premixed propane\u00a0flame more prone to wrinkling under turbulent conditions. Future testing in the 20-L explosion chamber is\u00a0suggested.<\/p>\n Download the complete paper here<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" Alfonso Ibarreta, Ph.D., PE, CFEI, Timothy Myers, Ph.D., PE, CFEI, CFI, James Bucher, Ph.D., CFEI and Kevin Marr, Ph.D., CFEI Exponent, USA Presented at\u00a0International Symposium on Fire Investigation, 2012 ABSTRACT Natural gas, composed mainly of methane, is in some ways similar to propane gas. Both fuels have similar\u00a0energy densities per unit mass, and similar laminar … Continue reading Explosion Severity: Propane versus Natural Gas<\/span>